If you want the limits, I woulds say that Herodotus with 100,000 workers and Wier with 10,000 are the opposite limits.

Wier is the most particular one with his calculations based on the potential energy of the stone in the Great Pyramid [the potential energy, expressed in joule, is the energy that an object has got at a certain height; to carry that object there you need to consume that energy, regardless how you do]. In other words, the potential energy of a block at a height of 100mt is equal to 100mt multiplied the weight of the stone multiplied for "g", the factor of gravitational acceleration.

Then Wier, has considered the mean production of energy in joule of a common worker per day and the duration of the reign of Khufu [23 years, as for we know].

Now, Wier's method, even if scientific and fascinating, presents its own problems!

Personally [even if I know physics enough to follow his reasoning and check his calculations], I prefer an archaeological / historical approach:

Wier could be anyway near to reality ... they have found the village [town] where the workers lived. Archaeologists and Egyptologists have estimated that the capacity of this town was aroud 20,000 individuals. So we can forget about Herodotus and Wier has got anyway some troubles ... [why to build a wider village of what was necessary? Even if it's really probably that daily only about the 50% of the workers were in the construction site, but they had to enjoy periods of rest during the working season ...].

So, I stay with this limit numbers and probably on daily base the village wasn't always full. It's more difficult to estimate the activity of who lived near Giza [daily workers who kept on living in their homes].

[This is a nice summary, a quick read:

Standing Tall: Egypt’s Great Pyramids].